Method and apparatus for enhancing data retransmission to improve call performance

ABSTRACT

A method and apparatus for enhancing data retransmission to improve call performance are described. At least one protocol data unit (PDU) may be transmitted from a transmitting entity to a receiving entity. The at least one PDU may be part of a service data unit (SDU). It may be determined to perform a communication re-establishment. As such, the SDU may be retransmitted, beginning with a first PDU transmitted as part of the SDU. In an aspect, the transmitting entity may be a radio link control (RLC) transmitting device and the receiving entity may be an RLC receiving device in communication with one another across a network. In another aspect, the transmitting entity may be a radio link control (RLC) transmitting protocol layer and the receiving entity may be a radio link control (RLC) receiving protocol layer both within a protocol stack of a device.

CLAIM OF PRIORITY UNDER 35 U.S.C. §119

The present application for patent claims priority to ProvisionalApplication No. 61/680,007 entitled “METHODS AND APPAREATUSES FORENHANCING SERVICE DATA UNIT RETRANSMISSION FOR IMPROVING CALLPERFORMANCE” filed Aug. 6, 2012 and assigned to the assignee hereof andhereby expressly incorporated by reference herein.

BACKGROUND

1. Field

Aspects of the present disclosure relate generally to wirelesscommunication systems, and more particularly, to enhancing dataretransmission to improve call performance.

2. Background

Wireless communication networks are widely deployed to provide variouscommunication services such as telephony, video, data, messaging,broadcasts, and so on. Such networks, which are usually multiple accessnetworks, support communications for multiple users by sharing theavailable network resources. One example of such a network is the UMTSTerrestrial Radio Access Network (UTRAN). The UTRAN is the radio accessnetwork (RAN) defined as a part of the Universal MobileTelecommunications System (UMTS), a third generation (3G) mobile phonetechnology supported by the 3rd Generation Partnership Project (3GPP).The UMTS, which is the successor to Global System for MobileCommunications (GSM) technologies, currently supports various airinterface standards, such as Wideband-Code Division Multiple Access(W-CDMA), Time Division-Code Division Multiple Access (TD-CDMA), andTime Division-Synchronous Code Division Multiple Access (TD-SCDMA). TheUMTS also supports enhanced 3G data communications protocols, such asHigh Speed Packet Access (HSPA), which provides higher data transferspeeds and capacity to associated UMTS networks.

As the demand for mobile broadband access continues to increase,research and development continue to advance the UMTS technologies notonly to meet the growing demand for mobile broadband access, but toadvance and enhance the user experience with mobile communications.

For example, as per the radio link control (RLC) layer protocol,whenever a user equipment (UE) (or other message-transmitting device,such as a Node B) receives a RESET command from a peer RLC entity, whichmay be a message-receiving device (such as a UE or network entity, e.g.,a Node B or radio network controller), the UE will discard allpreviously transmitted protocol data units (PDUs). The UE may storethese previously transmitted PDUs, which may be part of a larger servicedata unit (SDU), in a buffer when they have not yet been acknowledged ashaving been received by a receiving entity. Additionally, the UEdiscards any portions of partially-transmitted SDUs pending in atransmission queue at the UE (e.g., some PDUs of the SDU have beentransmitted and some PDUs of the SDU are pending transmission in thetransmission queue). After completion of this discarding procedure, theUE resumes transmission, starting with an SDU that came after thediscarded SDU in the transmission queue. As such, an SDU, or PDUS of theSDU, may be lost.

Furthermore, when a message is transmitted in the uplink (UL) and aradio link control (RLC) re-establishment indication is concurrentlyreceived in the downlink (DL), the transmitted message and associatedPDUs are discarded. Though the RLC protocol layer indicates the failureof the signaling message to a radio resource controller (RRC), the RRCdoes not include instructions for recovery of the transmitted message.As a result, the lost signaling message is not retransmitted by the RLCor upper layers. This can lead to a deadlock in the signaling proceduresuch that subsequent SDUs are not processed by a receiver. In someinstances, this will lead to call release.

Thus improvements in message and data transmission in communicationsnetworks to avoid lost messages, data, and call release are desired.

SUMMARY

The following presents a simplified summary of one or more aspects inorder to provide a basic understanding of such aspects. This summary isnot an extensive overview of all contemplated aspects, and is intendedto neither identify key or critical elements of all aspects nordelineate the scope of any or all aspects. Its sole purpose is topresent some concepts of one or more aspects in a simplified form as aprelude to the more detailed description that is presented later.

In an aspect, a method for wireless communication is described. Themethod may include transmitting at least one protocol data unit (PDU)from a transmitting entity to a receiving entity. The at least one PDUmay be part of a service data unit (SDU). The method may includedetermining to perform a communication re-establishment. The method mayinclude retransmitting the SDU, beginning with a first PDU transmittedas part of the SDU, in response to determining to perform thecommunication re-establishment.

In an aspect, a computer program product for wireless communication isdescribed. The computer program product may include a computer-readablemedium comprising code. The code may cause a computer to transmit atleast one protocol data unit (PDU) from a transmitting entity to areceiving entity. The at least one PDU may be part of a service dataunit (SDU). The code may cause a computer to determine to perform acommunication re-establishment. The code may cause a computer toretransmit the SDU, beginning with a first PDU transmitted as part ofthe SDU, in response to determining to perform the communicationre-establishment.

In an aspect, an apparatus for wireless communication is described. Theapparatus may include means for transmitting at least one protocol dataunit (PDU) from a transmitting entity to a receiving entity. The atleast one PDU may be part of a service data unit (SDU). The apparatusmay include means for determining to perform a communicationre-establishment. The apparatus may include means for retransmitting theSDU, beginning with a first PDU transmitted as part of the SDU, inresponse to determining to perform the communication re-establishment.

In an aspect, an apparatus for wireless communication is described. Theapparatus may include at least one memory and a communication manager incommunication with the memory. The communication manager may beconfigured to transmit at least one protocol data unit (PDU) from atransmitting entity to a receiving entity. The at least one PDU may bepart of a service data unit (SDU). The communication manager may beconfigured to determine to perform a communication re-establishment. Thecommunication manager may be configured to retransmit the SDU, beginningwith a first PDU transmitted as part of the SDU, in response todetermining to perform the communication re-establishment.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed aspects will hereinafter be described in conjunction withthe appended drawings, provided to illustrate and not to limit thedisclosed aspects, wherein like designations denote like elements, andin which:

FIG. 1 is a block diagram of an example wireless system, including areceiving entity and a transmitting entity in communication with oneanother;

FIG. 2 is a block diagram of a communication manager according toaspects of the present disclosure;

FIG. 3 is a block diagram illustrating an example of a computer devicehaving aspects of the present disclosure;

FIG. 4 is a flow chart of a method for improved message transmissionaccording to aspects of the present disclosure;

FIG. 5 is a flow chart of a method for improved message transmissionbetween an RLC transmitting device and an RLC receiving device accordingto aspects of the present disclosure;

FIG. 6 is a flow chart of a method for improved message transmissionbetween an RLC transmitting protocol layer and an RLC receiving protocollayer according to aspects of the present disclosure

FIG. 7 is a message flow diagram of communications between an RLCreceiving device and an RLC transmitting device;

FIG. 8 is a message flow diagram of communications between a receivingentity within an RLC receiving protocol layer and a transmitting entitywithin an RLC transmitting protocol layer;

FIG. 9 is a block diagram of an example hardware implementation for anapparatus employing a processing system;

FIG. 10 is a block diagram of an example of a telecommunications system;

FIG. 11 is a block diagram of an example of an access network;

FIG. 12 is a block diagram of an example of a radio protocolarchitecture for the user and control plane; and

FIG. 13 is a block diagram of an example of a Node B in communicationwith a UE in a telecommunications system.

DETAILED DESCRIPTION

Various aspects are now described with reference to the drawings. In thefollowing description, for purposes of explanation, numerous specificdetails are set forth in order to provide a thorough understanding ofone or more aspects. It may be evident, however, that such aspect(s) maybe practiced without these specific details.

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

The present disclosure teaches methods and apparatus for improvedmessage communication after a device, or protocol layer, determines thatall or part of a previously-transmitted message should be discarded inresponse to a re-establishment.

In an aspect, a network (e.g., a network entity) may determine toperform a re-establishment as between two radio link controller (RLC)peer entities (e.g., an RLC receiving device and an RLC transmittingdevice). In an aspect, a network (e.g., a network entity) may determineto perform a re-establishment between two protocol layers (e.g., an RLCreceiving protocol layer and an RLC transmitting protocol layer) withina protocol stack of a single device, such as, for example, a userequipment (UE) or another network entity (e.g., a Node B). The network(e.g., a network entity) may determine to perform the re-establishmentfor a variety of reasons, including, in non-limiting examples: to adjustRLC packet data unit (PDU) size or some other RLC configuration, duringa state transition from cell forward access channel (CELL_FACH) to celldedicated channel (CELL_DCH), and/or during a radio network controller(RNC) relocation in which case the RLC layer may be established on thenew RNC network entity, or the like. Alternatively, or in addition, areceiving entity and/or a transmitting entity may be configured todetermine that a re-establishment condition exists, such as, innon-limiting examples: a maximum number of PDU retransmissions has beenreached, a threshold bad channel quality value has been met or exceeded,or some other metric.

In an aspect, two RLC peer devices may be in communication with oneanother across a network. An RLC transmitting device may receive an RLCRESET command from an RLC receiving device when a service data unit(SDU) has only been partially transmitted by the RLC transmitting device(e.g., less than all of the packet data units (PDUs) that make up an SDUhave been transmitted), the RLC transmitting device may initiate an SDUdiscard procedure, such that the RLC transmitting device may push thepreviously transmitted PDUs to a transmission queue, discard thepreviously transmitted PDUs from a buffer, and retransmit the full SDUstarting at the first byte of the first PDU of the SDU.

Similarly, where any SDUs have been fully transmitted by the RLCtransmitting device but have not yet been acknowledged by the RLCreceiving device before receipt of the RLC RESET command, the RLCtransmitting device may push such SDUs back into the transmission queuefor full retransmission beginning at their first bytes. Through suchoperation, the changes of signaling radio bearer (SRB) andpacket-switched radio access bearer (RAB) data transmissions that mightotherwise trigger an RLC unrecoverable error and result in acircuit-switched call drop can be minimized. Furthermore, even thoughsome lost SDUs may be recovered according to Transmission ControlProtocol (TCP) level retransmissions according relevant standards, thepresent methods and apparatus obviate throughput degradation associatedwith executing TCP backoff algorithms when TCP packets are lost.

In another aspect, a radio link control (RLC) transmitting protocollayer and an RLC receiving protocol layer may be within a protocol stackof a single device, such as, for example, a user equipment or anothernetwork entity (e.g., a Node B). The RLC transmitting protocol layer maytransmit PDUs to the RLC receiving protocol layer. The RLC transmittingprotocol layer may receive a message (e.g., a layer 3 message) from theRLC receiving protocol layer indicating a communicationre-establishment. The re-establishment message may be received when oneor more PDUs have only been partially transmitted to the RLC receivingprotocol layer and/or the re-establishment message may be received afterone or more PDUs have been transmitted to the RLC receiving protocollayer, but before being acknowledged. In response to there-establishment message, the RLC transmitting protocol layer mayinitiate a discard procedure such that the RLC transmitting protocollayer may push the previously transmitted PDUs to a transmission queue,discard the previously transmitted PDUs from a buffer, and retransmitthe PDUs starting at the first byte of an SDU made up of the PDUs.

Referring to FIG. 1, a wireless communication system 100 is illustratedthat facilitates improved data retransmission between a receiving entity110 and a transmitting entity 150 in communication with a base station190. In an aspect, receiving entity 110 and/or transmitting entity 150may be peer radio link control (RLC) devices. In another aspect,receiving entity 110 and/or transmitting entity 150 may be protocollayers within a single device in communication with a network via basestation 190. More particularly, and in the aspect, receiving entity 110and/or transmitting entity 150 may be a radio resource control (RRC)protocol layer and/or a radio link controller (RLC) protocol layerwithin the single device.

Receiving entity 110 and/or transmitting entity 150 may be, or may bewithin, a mobile apparatus or a network entity. The mobile apparatus iscommonly referred to as a user equipment (UE) in UMTS applications, andmay be referred to as such throughout the present disclosure. A mobileapparatus also may be referred to as a mobile station, a subscriberstation, a mobile unit, a subscriber unit, a wireless unit, a remoteunit, a mobile device, a wireless device, a wireless communicationsdevice, a remote device, a mobile subscriber station, an accessterminal, a mobile terminal, a wireless terminal, a remote terminal, ahandset, a terminal, a user agent, a mobile client, a client, or someother suitable terminology. A network entity may be, for example, anaccess point, base station (BS), Node B, a relay, a peer-to-peer device,an authentication, authorization and accounting (AAA) server, a mobileswitching center (MSC), a radio network controller (RNC), or the like.

Receiving entity 110 includes receiving communication manager 120 andtransmitting entity 150 includes transmitting communication manager 160,each of which may be configured to manage the communication behavior ofits host entity. Such behavior may include, for example, transmittingmessages, receiving messages, processing messages, and/or managing PDUand/or SDU transmission and retransmission behavior of the receivingentity 110 and transmitting entity 150, respectively.

Transmitting communication manager 160 may be configured to transmit anSDU transmission 102, e.g. transmitting at least one PDU that is part ofthe SDU, to receiving entity 110. Subsequently, a communicationre-establishment 104 may take place between transmitting entity 150 andreceiving entity 110. The network (e.g., an RNC) may determine toperform the re-establishment for a variety of reasons, including, innon-limiting examples: to adjust RLC packet data unit (PDU) size or someother RLC configuration, during a state transition from cell forwardaccess channel (CELL_FACH) to cell dedicated channel (CELL_DCH), and/orduring a radio network controller (RNC) relocation in which case the RLClayer may be established on the new RNC network entity, or the like.Alternatively, or in addition, receiving entity 110 and/or transmittingentity 150 may be configured to determine that a re-establishmentcondition exists, such as, in non-limiting examples: a maximum number ofPDU retransmissions has been reached, a threshold bad channel qualityvalue has been met or exceeded, or some other metric.

Various communications and processes may take place between receivingentity 110 and transmitting entity 150 to perform, and complete, there-establishment. Re-establishment 104 of FIG. 1 represents such aspectsof a re-establishment as between receiving entity 110 and transmittingentity 150.

In the aspect where receiving entity 110 and/or transmitting entity 150are peer RLC devices, for example, transmitting entity 150 and/orreceiving entity 110 may transmit and/or receive an RLC RESET commandand respond with an RLC RESET acknowledgment command. In the aspect, there-establishment 104 also may include transmitting entity 150 and/orreceiving entity 110 transmitting and/or receiving a move receive window(MRW) command and an MRW acknowledgment command.

In the aspect where receiving entity 110 and/or transmitting entity 150are protocol layers within a single device, the re-establishment 104 mayinclude receiving a layer 3 (L3) radio resource control (RRC) messagefrom the network, via, e.g., base station 190, indicating that a radiolink controller (RLC) entity (e.g., the RLC layer, which may comprisereceiving entity 110 and/or transmitting entity 150) may bere-established.

Upon completion of the re-establishment 104, transmitting entity 150,via transmitting communication manager 160, may be configured to send anacknowledgment message (not shown), and retransmit the SDU, e.g., SDUretransmission 106, beginning with a first PDU transmitted as part ofthe SDU, to receiving entity 110.

Referring to FIG. 2, a communication manager 200 may be configured to,in non-limiting examples, transmit messages, receive messages, processmessages, and/or manage PDU and/or SDU transmission and retransmissionbehavior of its host entity. Communication manager 200 may betransmitting communication manager 160 within transmitting entity 150and/or receiving communication manager 120 within receiving entity 110.

Communication manager 200 may include a PDU/SDU transmitter andretransmitter 201, which may be configured to transmit and potentiallyretransmit one or more PDUs of one or more SDUs. PDU/SDU transmitter andretransmitter 201 may be a transmitter, antenna and operationalcircuitry, a transceiver, or the like.

Furthermore, communication manager 200 may include a transmission queuemanager 202, which may be configured to control and manage the behavior,addressing, contents, order of transmission, or the like of PDUs andSDUs to be transmitted to a receiving entity. Transmission queue 203 maybe a memory, or data store, that is able to store and organize PDUs andmay communicate with PDU/SDU transmitter and retransmitter 201 fortransmission or retransmission of the PDUs and SDUs.

In an aspect, transmission queue manager 202 also may be configured toreceive one or more previously transmitted PDUs or SDUs from atransmitted PDU/SDU buffer 204, which may store the contents ofpreviously transmitted messages for potential retransmission.Transmitted PDU/SDU buffer 204 may include circuitry or may utilize aprocessor to copy one or more previously transmitted PDUs and SDUsstored in the buffer and push one or more unacknowledged PDUs into thetransmission queue 203 for retransmission, beginning at the first byteof the first previously transmitted PDU of a previously-transmitted SDU.

Furthermore, communication manager 200 may include a PDU/SDU discardingcomponent 205, which may be configured to initiate a discard procedure,which may signal the communication manager 200 to copy anyunacknowledged PDUs or SDUs in the transmitted PDU/SDU buffer 204 and/orpush these unacknowledged PDUs or SDUs or their copies into thetransmission queue 203. Furthermore, once the unacknowledged PDUs orSDUs have been pushed into the transmission queue 203, PDU/SDUdiscarding component 205 may discard the previously transmitted PDUs orSDUs from the transmitted PDU/SDU buffer 204 or another storagelocation.

In an additional aspect, PDU/SDU discarding component 205 may include are-establishment component 206, which may be configured to determine toperform a communication re-establishment.

For example, in an aspect where receiving entity 110 and/or transmittingentity 150 are RLC peer devices, re-establishment component 206 may,optionally, be configured to initiate an SDU discard procedure based onreceiving a communication re-establishment message from receiving entity110, transmitting entity 150, and/or the network. Further, in an aspect,re-establishment component 206 may be configured to initiate an SDUdiscard procedure based on determining that a re-establishment conditionexists.

In the RLC peer device aspect, re-establishment component 206 mayinclude an RLC reset component 207 and a move receive window (MRW)operation component 208. In an aspect, the re-establishment message maybe an RLC RESET command, and communication manager 200 may be configuredto initiate the SDU discard procedure based on determining to perform acommunication re-establishment and/or receiving an RLC RESET commandfrom a receiving device. For example, communication manager 200 maydetermine to perform a communication re-establishment based on anindication from the network, via base station 190, or some othercomponent. In another example, communication manager 200 may beconfigured to determine that a re-establishment condition exists and, inresponse, initiate the SDU discard procedure, and send, to a receivingdevice, an RLC RESET command.

Communication manager 200 may be configured to determine whether the SDUdiscard procedure has been successfully completed. For example,successful completion may be based on determining that the previouslytransmitted PDUs or SDUs have been discarded from the transmittedPDU/SDU buffer 204 and/or pushed to the transmission queue 203.Furthermore, the RLC reset component 207 may be configured to transmitan RLC RESET acknowledgement message (ACK) upon receipt of an RLC RESETmessage or upon successful completion of the SDU discard procedure.

In the RLC peer device aspect, re-establishment component 206 also mayinclude MRW operation component 208, which may be configured togenerate, transmit and/or receive an MRW command or MRW commandacknowledgment. In one aspect, PDU/SDU discarding component 205, incombination with MRW operation component 208, may be configured todetermine whether an SDU discard procedure has been successfullycompleted by transmitting an MRW command to an RLC receiving device andreceiving an MRW command acknowledgment message from the receivingdevice indicating that the receiving device has discarded the SDU andhas moved a receive window in preparation for receiving a retransmittedSDU and/or PDUs. In another aspect, PDU/SDU discarding component 205and/or MRW operation component 208 may be configured to determinewhether an SDU discard procedure has been successfully completed byreceiving an MRW command from an RLC receiving device and sending an MRWcommand acknowledgment message to the receiving device indicating thatthe transmitting device has discarded the SDU and has moved a receivewindow in preparation for receiving a retransmitted SDU. An entityreceiving an MRW command may identify one or more previously-receivedSDUs that are to be discarded or should not be expected to arrive. Theentity receiving the MRW command may then discard thepreviously-received SDUs, move its receive window to avoid any delayassociated with waiting for SDUs that have not yet been received andhave been discarded at the transmitting device, and generate andtransmit an MRW command acknowledgment to the device from which itreceived the MRW command.

In an aspect where receiving entity 110 and transmitting entity 150 areprotocol layers within a single device in communication with a network,re-establishment component 206 may be configured to receive an L3 RRCmessage from the network indicating a communication re-establishment.The re-establishment component 206 also may be configured to send an L3RRC response message to the network. In the RLC protocol layer aspect,re-establishment component 206 may, optionally, include RLC resetcomponent 207 and MRW operation component 208, which may operate asdescribed herein, after transmission of the response message.

In any event, upon completion of the re-establishment procedure, thePDU/SDU discarding component 205 may communicate to PDU/SDU transmitterand retransmitter 201 that the partially transmitted and/orunacknowledged SDUs have been successfully moved to the transmissionqueue 203. As such, the PDU/SDU transmitter and retransmitter 201 mayretransmit the one or more SDUs beginning at the first byte of the firstPDU of the SDU. Furthermore, re-establishment component 206 may beconfigured to return an acknowledgment message to the receiving entityto indicate that the re-establishment procedure has been successfullycompleted.

Referring to FIG. 3, in one aspect, a communication manager 200 may berepresented by a specially programmed or configured computer device 300.Communication manager 200, which may operate as described herein withrespect to FIG. 2, may be receiving communication manager 120 and/ortransmitting communication manager 160. For example, the specialprogramming or configuring of computer device 300 may be programming orconfiguring to perform that respective functions described herein forthe respective entity, such as receiving communication manager 120and/or transmitting communication manager 160.

Computer device 300 includes a processor 302 specially configured tocarry out processing functions associated with one or more of componentsand functions described herein with respect to communication manager 200and its components. Processor 302 can include a single or multiple setof processors or multi-core processors. Moreover, processor 302 can beimplemented as an integrated processing system and/or a distributedprocessing system.

Computer device 300 further includes a memory 304, such as for storingdata used herein and/or local versions of applications and/orinstructions or code being executed by processor 302, such as to performthe functions of the respective entities described herein. Memory 304can include any type of memory usable by a computer, such as randomaccess memory (RAM), read only memory (ROM), tapes, magnetic discs,optical discs, volatile memory, non-volatile memory, and any combinationthereof. In an aspect, memory 304 may include transmitted PDU/SDU buffer204 and/or transmission queue 203.

Further, computer device 300 includes a communications component 306that provides for establishing and maintaining communications with oneor more parties utilizing hardware, software, and services as describedherein. Communications component 306 may carry communications betweencomponents on computer device 300, as well as between computer device300 and external devices, such as devices located across acommunications network and/or devices serially or locally connected tocomputer device 300. For example, communications component 306 mayinclude one or more buses, and may further include transmit chaincomponents and receive chain components associated with a transmitterand receiver, respectively, or a transceiver, operable for interfacingwith external devices. In an aspect, communications component 306 mayinclude PDU/SDU transmitter and retransmitter 201.

Additionally, computer device 300 may further include a data store 308,which can be any suitable combination of hardware and/or software, thatprovides for mass storage of information, databases, and programsemployed in connection with aspects described herein. For example, datastore 308 may be a data repository for applications not currently beingexecuted by processor 302. In an aspect, data store 308 may includetransmitted PDU/SDU buffer 204 and/or transmission queue 203.

Computer device 300 may additionally include a user interface component310 operable to receive inputs from a user of computer device 300, andfurther operable to generate outputs for presentation to the user. Userinterface component 310 may include one or more input devices, includingbut not limited to a keyboard, a number pad, a mouse, a touch-sensitivedisplay, a navigation key, a function key, a microphone, a voicerecognition component, any other mechanism capable of receiving an inputfrom a user, or any combination thereof. Further, user interfacecomponent 310 may include one or more output devices, including but notlimited to a display, a speaker, a haptic feedback mechanism, a printer,any other mechanism capable of presenting an output to a user, or anycombination thereof. In an additional aspect, a user using the userinterface component 310 may set one of a first subscription or a secondsubscription as a dedicated data service (DDS) for the computer device300.

Referring to FIG. 4, a method 400 for improved message transmissionaccording to aspects of the present disclosure is shown. The method 400may be performed by receiving entity 110 and/or transmitting entity 150.In an aspect, the transmitting entity and the receiving entity are RLCpeer devices. In another aspect, the transmitting entity and thereceiving entity are protocol layers within a single device.

At 410, the method 400 includes transmitting at least one protocol dataunit (PDU) from a transmitting entity to a receiving entity, wherein theat least one PDU is part of a service data unit (SDU). In an aspect,communication manager 200 (which may be receiving communication manager120 and/or transmitting communication manager 160) and/or PDU/SDUtransmitter and retransmitter 201 may be configured to transmit at leastone PDU, which is part of an SDU, to receiving entity 110.

At 420, the method 400 includes determining to perform a communicationre-establishment. In an aspect, communication manager 200 (which may bereceiving communication manager 120 and/or transmitting communicationmanager 160), PDU/SDU discarding component 205, and/or re-establishmentcomponent 206 may be configured to determine to perform a communicationre-establishment based on an indication from the network or anothercomponent and/or based on determining that a re-establishment conditionexists. Additionally, further aspects of determining to perform acommunication re-establishment are described herein in reference toaction 520 of FIG. 5 and action 620 of FIG. 6.

At 430, the method 400 includes retransmitting the SDU, beginning with afirst PDU transmitted as part of the SDU, in response to determining toperform the communication re-establishment. In an aspect, communicationmanager 200 (which may be receiving communication manager 120 and/ortransmitting communication manager 160) and/or PDU/SDU transmitter andretransmitter 201 may be configured to retransmit the SDU in response todetermining to perform the communication re-establishment. For example,and in an aspect, the SDU may be retransmitted after completion of there-establishment.

Referring to FIG. 5, a method 500 includes additional aspects of method400 for improved message transmission according to aspects of thepresent disclosure. The method 500 may be performed by transmittingentity 150 and/or receiving entity 110. More particularly, and in anaspect, the receiving entity 110 and/or transmitting entity 150 ofmethod 500 may be peer RLC devices.

At 520, the method 500, which may be similar to 420 of method 400,includes determining to perform a communication re-establishment. In theexample of method 500, the action of 520 may include actions 522, 524,and 526.

At 522, the method 500 may include initiating an SDU discard procedure.For example, communication manager 200 (which may include receivingcommunication manager 120 and/or transmitting communication manager 160)may be configured to initiate an SDU discard procedure. The SDU discardprocedure may be initiated based on communication manager 200determining to perform the communication re-establishment as describedherein.

At 524, the method 500 may include performing the SDU discard procedure.For example, transmitting entity 150, communication manager 200 (whichmay be transmitting communication manager 160), and/or PDU/SDUdiscarding component 205 may perform an SDU discard procedure. The SDUdiscard procedure may include determining that at least one or more PDUsassociated with the SDU have not been acknowledged by receiving entity110 and/or because the SDU has only been partially-transmitted toreceiving entity 110. The SDU discard procedure may include moving theSDU to a transmission queue, in an original order, for retransmission ofthe SDU to receiving entity 110, as described herein.

At 526, the method 500 may include determining that the SDU discardprocedure has been successfully completed. In an aspect, thetransmitting entity 150, communication manager 200 (which may betransmitting communication manager 160), and/or PDU/SDU discardingcomponent determines that the SDU discard procedure has beensuccessfully completed.

In an aspect, receiving entity 110, communication manager 200 (which maybe receiving communication manager 120), and/or PDU/SDU discardingcomponent 205 may initiate an SDU discard procedure and determine thatit has been successfully completed.

Referring to FIG. 6, a method 600 includes additional aspects of method400 for improved message transmission according to aspects of thepresent disclosure. The method 600 may be performed by receiving entity110 and/or transmitting entity 150. More particularly, and in an aspect,receiving entity 110 and/or transmitting entity 150 may be protocollayers within a single device in communication with a network. Forexample, receiving entity 110 and/or transmitting entity 150 may be anRRC layer and/or an RLC layer within the single device.

At 620, which may be similar to 420 of method 400, the method 600includes determining to perform a communication re-establishment. In theexample of method 600, action 620 may include actions 622, 624, and 626.

At 622, the method 600 includes receiving a message indicating thecommunication re-establishment. An L3 RRC message may be received fromthe network indicating a communication re-establishment. For example,transmitting entity 150, communication manager 200 (which may betransmitting communication manager 160), PDU/SDU discarding component205, and/or re-establishment component 206 may receive a messageindicating the communication re-establishment as described herein.

At 624, the method 600 includes performing an SDU discard procedure.Receiving entity 110, transmitting entity 150, communication manager 200(which may be receiving communication manager 120 and/or transmittingcommunication manager 160), and/or PDU/SDU discarding component 205 mayperform an SDU discard procedure. The SDU discard procedure may includedetermining that at least one or more PDUs associated with the SDU havenot been acknowledged by receiving entity 110 and/or because the SDU hasonly been partially-transmitted to receiving entity 110. The SDU discardprocedure may include moving the SDU to a transmission queue, in anoriginal order, for retransmission of the SDU to receiving entity 110,as described herein.

At 626, the method 600 includes determining that the re-establishmenthas been successfully completed. Transmitting entity 150, receivingentity 110, communication manager 200 (which may be receivingcommunication manager 120 and/or transmitting communication manager160), PDU/SDU discarding component 205, and/or re-establishmentcomponent 206 may determine that the re-establishment has beensuccessfully completed and, as a result, the SDU is ready forretransmission.

Referring to FIG. 7, a message flow 700 shows communication betweenreceiving entity 110, including receiving communication manager 120, andtransmitting entity 150, including transmitting communication manager160, according to an aspect of the present disclosure. The actionsdescribed herein with respect to message flow 700 may be performed byreceiving communication manager 120 and/or transmitting communicationmanager 160. More particularly, and in the example of FIG. 7, thereceiving entity 110 and/or transmitting entity 150 may be peer RLCdevices.

At 751, transmitting entity 150 begins transmission of an SDU 730 bysending PDU#1. For example, SDU 730 may have been divided into four PDUs(PDU#1, PDU#2, PDU#3, and PDU#4) for transmission.

At 752, transmitting entity 150 transmits PDU#2 to receiving entity 110.At 753, transmitting entity 150 transmits PDU#3 to receiving entity 110.As such, and in the example, only three of the four PDUs that make upSDU 730 have been transmitted to receiving entity 110. Thus, SDU 730 hasonly been partially-transmitted by transmitting entity 150 to receivingentity 110 at this point. Furthermore, and for example, SDU 730 may notbe acknowledged (as received) by receiving entity 110 because it has notbeen completely transmitted (e.g., PDU#4 has not yet been transmitted).

At 754, transmitting entity 150 receives an RLC RESET command fromreceiving entity 110. The RLC RESET command may have been triggeredbased on a determination to perform a communication re-establishment.

At 755, transmitting entity 150 initiates an SDU discard procedure. Asdescribed herein, transmitting entity 150, via transmittingcommunication manager 160, may be configured to movepreviously-transmitted, but not acknowledged, PDUs and SDUs to thetransmission queue 743. For example, SDU 730, including PDU#1, PDU#2,PDU#3, and PDU#4, is moved, or copied, into s transmission queue.

At 756, transmitting entity 150 sends an MRW command to receiving entity110, as described herein.

At 757, transmitting entity 150 determines that PDU#1, PDU#2, and PDU#3have not been acknowledged by receiving entity 110.

At 758, and upon receipt of the MRW command, receiving entity 110discards the previously-received SDUs, and, at 759, moves its receivewindow to account for PDUs and SDUs that it will not receive (e.g., PDUsand SDUs discarded at transmitting entity 150) andpreviously-transmitted PDUs and SDUs that will be retransmitted and, assuch, it may receive again.

At 760, receiving entity 110 transmits an MRW acknowledgment command totransmitting entity 150. At 761, and upon determining successfulcompletion of the SDU discard procedure, RLC transmitting devicetransmits an RLC RESET acknowledgment command to receiving entity 110.Transmitting entity 150 may determine that the SDU discard procedure hasbeen successfully completed based on receiving the MRW acknowledgmentcommand indicating that the RLC receiving device has discarded the SDUand has moved the receive window in preparation for receiving theretransmitted SDU.

In an aspect (not shown), transmitting entity 150 may send the RLC RESETcommand to receiving entity 110 and, in response, receive the RLC RESETcommand acknowledgment. In an aspect (also not shown), transmittingentity 150 may receive the MRW command from receiving entity 110 andrespond with an MRW command acknowledgment.

At 762, transmitting entity 150 retransmits SDU 730, starting with thefirst byte of the first PDU (e.g., PDU#1), to receiving entity 110.PDU#2 is retransmitted at 763, PDU#3 is retransmitted at 764, and PDU#4is retransmitted at 765.

Referring to FIG. 8, a message flow 800 shows communication betweenreceiving entity 110, including receiving communication manager 120, andtransmitting entity 150, including transmitting communication manager160 according to aspects of the present disclosure. The actionsdescribed herein with respect to message flow 700 may be performed byreceiving communication manager 120 and/or transmitting communicationmanager 160. More particularly, and in the example of FIG. 8, receivingentity 110 and/or transmitting entity 150 may be protocol layers withina single device in communication with a network. For example, receivingentity 1109 and/or transmitting entity 150 may be an RRC layer and/or anRLC layer within the single device.

At 851, transmitting entity 150 begins transmission of an SDU 830. Forexample, SDU 830 may have been divided into four PDUs (PDU#1, PDU#2,PDU#3, and PDU#4) for transmission. At 852, transmitting entity 150transmits PDU#2, and at 853, transmitting entity 150 transmits PDU#3. Assuch, and for example, by only transmitting PDU#1, PDU#2, and PDU#3, SDU830 has only been partially-transmitted by transmitting entity 150 toreceiving entity 110 at this point. Furthermore, and for example, SDU830 may not be acknowledged (as received) by receiving entity 110because it has not been completely transmitted (e.g., PDU#4 has not yetbeen transmitted).

At 854, transmitting entity 150 receives an RLC RE-ESTABLISHMENT commandfrom receiving entity 110. The receiving entity 110 may send the RLCRE-ESTABLISHMENT command based on receiving an L3 RRC message from thenetwork indicating that the RLC entity id to be re-established. In thisexample, and in an aspect, receiving entity 110 may be an RRC protocollayer within the same device as transmitting entity 150, which may be,in the aspect, an RLC protocol layer.

At 855, transmitting entity 150 initiates the re-establishmentprocedure. The re-establishment procedure may be performed bytransmitting entity 150, via transmitting communication manager 160, asdescribed herein with respect to FIG. 2. At 856, transmitting entity 150determines that the re-establishment was successfully completed. Assuch, transmitting entity 150 may be prepared to re-send SDU 830,beginning with the first byte of PDU#1 of SDU 830.

At 857, transmitting entity 150 transmits an RLC RE-ESTABLISHMENTcommand acknowledgment to receiving entity 110. At 858, transmittingentity 150 begins re-transmitting the previously-transmitted SDU 830,starting with PDU#1, beginning with the first byte of the SDU 830.

FIG. 9 is a block diagram illustrating an example of a hardwareimplementation for an apparatus 900 employing a processing system 914,including communication manager 200 (which may be receivingcommunication manager 120 and/or transmitting communication manager160), for carrying out aspects of the present disclosure. In thisexample, the processing system 914 may be implemented with a busarchitecture, represented generally by a bus 902. The bus 902 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 914 and the overall designconstraints. The bus 902 links together various circuits including oneor more processors, represented generally by the processor 904,computer-readable media, represented generally by the computer-readablemedium 906, and one or more components described herein, such as, butnot limited to, communication manager 200. Communication manager 200, asdescribed herein, may be receiving communication manager 120 and/ortransmitting communication manager 160. The bus 902 also may linkvarious other circuits such as timing sources, peripherals, voltageregulators, and power management circuits, which are well known in theart, and therefore, will not be described any further. A bus interface908 provides an interface between the bus 902 and a transceiver 910. Thetransceiver 910 provides a means for communicating with various otherapparatus over a transmission medium. Depending upon the nature of theapparatus, a user interface 912 (e.g., keypad, display, speaker,microphone, joystick) also may be provided.

The processor 904 is responsible for managing the bus 902 and generalprocessing, including the execution of software stored on thecomputer-readable medium 906. The software, when executed by theprocessor 904, causes the processing system 914 to perform the variousfunctions described infra for any particular apparatus. Thecomputer-readable medium 906 also may be used for storing data that ismanipulated by the processor 904 when executing software. In aspects,communication manager 200 may be, for example, a separate physicalcomponent or a virtual component implemented by processor 904 operatingin conjunction with computer-readable medium 906 and bus interface 908.

The various concepts presented throughout this disclosure may beimplemented across a broad variety of telecommunication systems, networkarchitectures, and communication standards. By way of example andwithout limitation, the aspects of the present disclosure illustrated inFIG. 10 are presented with reference to a UMTS system 1000, in whichreceiving entity 110 and/or transmitting entity 150 may operate,employing a W-CDMA air interface. A UMTS network includes threeinteracting domains: a Core Network (CN) 1004, a UMTS Terrestrial RadioAccess Network (UTRAN) 1002, and User Equipment (UE) 1010. In an aspect,UE 1010 may be receiving entity 110 and/or transmitting entity 150. Inthis example, the UTRAN 1002 provides various wireless servicesincluding telephony, video, data, messaging, broadcasts, and/or otherservices. The UTRAN 1002 may include a plurality of Radio NetworkSubsystems (RNSs) such as an RNS 1007, each controlled by a respectiveRadio Network Controller (RNC) such as an RNC 1006. Here, the UTRAN 1002may include any number of RNCs 1006 and RNSs 1007 in addition to theRNCs 1006 and RNSs 1007 illustrated herein. The RNC 1006 is an apparatusresponsible for, among other things, assigning, reconfiguring, andreleasing radio resources within the RNS 1007. The RNC 1006 may beinterconnected to other RNCs (not shown) in the UTRAN 1002 throughvarious types of interfaces such as a direct physical connection, avirtual network, or the like, using any suitable transport network.

Communication between a UE 1010 and a Node B 1008 may be considered asincluding a physical (PHY) layer and a medium access control (MAC)layer. Further, communication between a UE 1010 and an RNC 1006 by wayof a respective Node B 1008 may be considered as including a radioresource control (RRC) layer. In the instant specification, the PHYlayer may be considered layer 1; the MAC layer may be considered layer7; and the RRC layer may be considered layer 3. Information hereinbelowutilizes terminology introduced in the RRC Protocol Specification, 3GPPTS 75.331 v9.1.0, incorporated herein by reference.

The geographic region covered by the RNS 1007 may be divided into anumber of cells, with a radio transceiver apparatus serving each cell. Aradio transceiver apparatus is commonly referred to as a Node B in UMTSapplications, but also may be referred to by those skilled in the art asa base station (BS), a base transceiver station (BTS), a radio basestation, a radio transceiver, a transceiver function, a basic serviceset (BSS), an extended service set (ESS), an access point (AP), or someother suitable terminology. For clarity, three Node Bs 1008 are shown ineach RNS 1007; however, the RNSs 1007 may include any number of wirelessNode Bs. The Node Bs 1008 provide wireless access points to a CN 1004for any number of mobile apparatuses, and may be the receiving entity110 and/or transmitting entity 150. Examples of a mobile apparatusinclude a cellular phone, a smart phone, a session initiation protocol(SIP) phone, a laptop, a notebook, a netbook, a smartbook, a personaldigital assistant (PDA), a satellite radio, a global positioning system(GPS) device, a multimedia device, a video device, a digital audioplayer (e.g., MP3 player), a camera, a game console, or any othersimilar functioning device. The mobile apparatus is commonly referred toas a UE in UMTS applications, but also may be referred to by thoseskilled in the art as a mobile station, a subscriber station, a mobileunit, a subscriber unit, a wireless unit, a remote unit, a mobiledevice, a wireless device, a wireless communications device, a remotedevice, a mobile subscriber station, an access terminal, a mobileterminal, a wireless terminal, a remote terminal, a handset, a terminal,a user agent, a mobile client, a client, or some other suitableterminology. In a UMTS system, the UE 1010 may further include auniversal subscriber identity module (USIM) 1011, which contains auser's subscription information to a network. For illustrative purposes,one UE 1010 is shown in communication with a number of the Node Bs 1008.The DL, also called the forward link, refers to the communication linkfrom a Node B 1008 to a UE 1010, and the UL, also called the reverselink, refers to the communication link from a UE 1010 to a Node B 1008.

The CN 1004 interfaces with one or more access networks, such as theUTRAN 1002. As shown, the CN 1004 is a GSM core network. However, asthose skilled in the art will recognize, the various concepts presentedthroughout this disclosure may be implemented in a RAN, or othersuitable access network, to provide UEs with access to types of CNsother than GSM networks.

The CN 1004 includes a circuit-switched (CS) domain and apacket-switched (PS) domain. Some of the circuit-switched elements are aMobile services Switching Centre (MSC), a Visitor location register(VLR) and a Gateway MSC. Packet-switched elements include a Serving GPRSSupport Node (SGSN) and a Gateway GPRS Support Node (GGSN). Some networkelements, like EIR, HLR, VLR and AuC may be shared by both of thecircuit-switched and packet-switched domains. In the illustratedexample, the CN 1004 supports circuit-switched services with a MSC 1012and a GMSC 1014. In some applications, the GMSC 1014 may be referred toas a media gateway (MGW). One or more RNCs, such as the RNC 1006, may beconnected to the MSC 1012. The MSC 1012 is an apparatus that controlscall setup, call routing, and UE mobility functions. The MSC 1012 alsoincludes a VLR that contains subscriber-related information for theduration that a UE is in the coverage area of the MSC 1012. The GMSC1014 provides a gateway through the MSC 1012 for the UE to access acircuit-switched network 1016. The GMSC 1014 includes a home locationregister (HLR) 1015 containing subscriber data, such as the datareflecting the details of the services to which a particular user hassubscribed. The HLR is also associated with an authentication center(AuC) that contains subscriber-specific authentication data. When a callis received for a particular UE, the GMSC 1014 queries the HLR 1015 todetermine the UE's location and forwards the call to the particular MSCserving that location.

The CN 1004 also supports packet-data services with a serving GPRSsupport node (SGSN) 1018 and a gateway GPRS support node (GGSN) 1020.GPRS, which stands for General Packet Radio Service, is designed toprovide packet-data services at speeds higher than those available withstandard circuit-switched data services. The GGSN 1020 provides aconnection for the UTRAN 1002 to a packet-based network 1022. Thepacket-based network 1022 may be the Internet, a private data network,or some other suitable packet-based network. The primary function of theGGSN 1020 is to provide the UEs 1010 with packet-based networkconnectivity. Data packets may be transferred between the GGSN 1020 andthe UEs 1010 through the SGSN 1018, which performs primarily the samefunctions in the packet-based domain as the MSC 1012 performs in thecircuit-switched domain.

An air interface for UMTS may utilize a spread spectrum Direct-SequenceCode Division Multiple Access (DS-CDMA) system. The spread spectrumDS-CDMA spreads user data through multiplication by a sequence ofpseudorandom bits called chips. The “wideband” W-CDMA air interface forUMTS is based on such direct sequence spread spectrum technology andadditionally calls for a frequency division duplexing (FDD). FDD uses adifferent carrier frequency for the UL and DL between a Node B 1008 anda UE 1010. Another air interface for UMTS that utilizes DS-CDMA, anduses time division duplexing (TDD), is the TD-SCDMA air interface. Thoseskilled in the art will recognize that although various examplesdescribed herein may refer to a W-CDMA air interface, the underlyingprinciples may be equally applicable to a TD-SCDMA air interface.

An HSPA air interface includes a series of enhancements to the 3G/W-CDMAair interface, facilitating greater throughput and reduced latency.Among other modifications over prior releases, HSPA utilizes hybridautomatic repeat request (HARQ), shared channel transmission, andadaptive modulation and coding. The standards that define HSPA includeHSDPA (high speed downlink packet access) and HSUPA (high speed uplinkpacket access, also referred to as enhanced uplink, or EUL).

HSDPA utilizes as its transport channel the high-speed downlink sharedchannel (HS-DSCH). The HS-DSCH is implemented by three physicalchannels: the high-speed physical downlink shared channel (HS-PDSCH),the high-speed shared control channel (HS-SCCH), and the high-speeddedicated physical control channel (HS-DPCCH).

Among these physical channels, the HS-DPCCH carries the HARQ ACK/NACKsignaling on the uplink to indicate whether a corresponding packettransmission was decoded successfully. That is, with respect to thedownlink, the UE 1010 provides feedback to the node B 1008 over theHS-DPCCH to indicate whether it correctly decoded a packet on thedownlink.

HS-DPCCH further includes feedback signaling from the UE 1010 to assistthe node B 1008 in taking the right decision in terms of modulation andcoding scheme and precoding weight selection, this feedback signalingincluding the CQI and PCI.

“HSPA Evolved” or HSPA+ is an evolution of the HSPA standard thatincludes MIMO and 64-QAM, enabling increased throughput and higherperformance. That is, in an aspect of the disclosure, the node B 1008and/or the UE 1010 may have multiple antennas supporting MIMOtechnology. The use of MIMO technology enables the node B 1008 toexploit the spatial domain to support spatial multiplexing, beamforming,and transmit diversity.

Multiple Input Multiple Output (MIMO) is a term generally used to referto multi-antenna technology, that is, multiple transmit antennas(multiple inputs to the channel) and multiple receive antennas (multipleoutputs from the channel). MIMO systems generally enhance datatransmission performance, enabling diversity gains to reduce multipathfading and increase transmission quality, and spatial multiplexing gainsto increase data throughput.

Spatial multiplexing may be used to transmit different streams of datasimultaneously on the same frequency. The data steams may be transmittedto a single UE 1010 to increase the data rate or to multiple UEs 1010 toincrease the overall system capacity. This is achieved by spatiallyprecoding each data stream and then transmitting each spatially precodedstream through a different transmit antenna on the downlink. Thespatially precoded data streams arrive at the UE(s) 1010 with differentspatial signatures, which enables each of the UE(s) 1010 to recover theone or more the data streams destined for that UE 1010. On the uplink,each UE 1010 may transmit one or more spatially precoded data streams,which enables the node B 1008 to identify the source of each spatiallyprecoded data stream.

Spatial multiplexing may be used when channel conditions are good. Whenchannel conditions are less favorable, beamforming may be used to focusthe transmission energy in one or more directions, or to improvetransmission based on characteristics of the channel. This may beachieved by spatially precoding a data stream for transmission throughmultiple antennas. To achieve good coverage at the edges of the cell, asingle stream beamforming transmission may be used in combination withtransmit diversity.

Generally, for MIMO systems utilizing n transmit antennas, n transportblocks may be transmitted simultaneously over the same carrier utilizingthe same channelization code. Note that the different transport blockssent over the n transmit antennas may have the same or differentmodulation and coding schemes from one another.

On the other hand, Single Input Multiple Output (SIMO) generally refersto a system utilizing a single transmit antenna (a single input to thechannel) and multiple receive antennas (multiple outputs from thechannel). Thus, in a SIMO system, a single transport block is sent overthe respective carrier.

Referring to FIG. 11, an access network 1100 in a UTRAN architecture isillustrated in which receiving entity 110 and/or transmitting entity 150may operate. Each of Nodes B 1142, 1144, 1146 and UEs 1130, 1132, 1134,1136, 1138, 1140, as shown in FIG. 11, may be receiving entity 110and/or transmitting entity 150 and may perform the aspects describedherein.

The multiple access wireless communication system includes multiplecellular regions (cells), including cells 1102, 1104, and 1106, each ofwhich may include one or more sectors. The multiple sectors can beformed by groups of antennas with each antenna responsible forcommunication with UEs in a portion of the cell. For example, in cell1102, antenna groups 1112, 1114, and 1116 may each correspond to adifferent sector. In cell 1104, antenna groups 1118, 1120, and 1122 eachcorrespond to a different sector. In cell 1106, antenna groups 1124,1126, and 1128 each correspond to a different sector. The cells 1102,1104 and 1106 may include several wireless communication devices, e.g.,User Equipment or UEs, which may be in communication with one or moresectors of each cell 1102, 1104 or 1106. For example, UEs 1130 and 1132may be in communication with Node B 1142, UEs 1134 and 1136 may be incommunication with Node B 1144, and UEs 1138 and 1140 can be incommunication with Node B 1146. Here, each Node B 1142, 1144, 1146 isconfigured to provide an access point to a CN 1004 (FIG. 10) for all theUEs 1130, 1132, 1134, 1136, 1138, 1140 in the respective cells 1102,1104, and 1106.

As the UE 1134 moves from the illustrated location in cell 1104 intocell 1106, a serving cell change (SCC) or handover may occur in whichcommunication with the UE 1134 transitions from the cell 1104, which maybe referred to as the source cell, to cell 1106, which may be referredto as the target cell. Management of the handover procedure may takeplace at the UE 1134, at the Node Bs corresponding to the respectivecells, at a radio network controller 1006 (FIG. 10), or at anothersuitable node in the wireless network. For example, during a call withthe source cell 1104, or at any other time, the UE 1134 may monitorvarious parameters of the source cell 1104 as well as various parametersof neighboring cells such as cells 1106 and 1102. Further, depending onthe quality of these parameters, the UE 1134 may maintain communicationwith one or more of the neighboring cells. During this time, the UE 1134may maintain an Active Set, that is, a list of cells that the UE 1134 issimultaneously connected to (i.e., the UTRA cells that are currentlyassigning a downlink dedicated physical channel DPCH or fractionaldownlink dedicated physical channel F-DPCH to the UE 1134 may constitutethe Active Set).

The modulation and multiple access scheme employed by the access network1100 may vary depending on the particular telecommunications standardbeing deployed. By way of example, the standard may includeEvolution-Data Optimized (EV-DO) or Ultra Mobile Broadband (UMB). EV-DOand UMB are air interface standards promulgated by the 3rd GenerationPartnership Project 2 (3GPP2) as part of the CDMA2000 family ofstandards and employs CDMA to provide broadband Internet access tomobile stations. The standard may alternately be Universal TerrestrialRadio Access (UTRA) employing Wideband-CDMA (W-CDMA) and other variantsof CDMA, such as TD-SCDMA; Global System for Mobile Communications (GSM)employing TDMA; and Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB),IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDMemploying OFDMA. UTRA, E-UTRA, UMTS, LTE, LTE Advanced, and GSM aredescribed in documents from the 3GPP organization. CDMA2000 and UMB aredescribed in documents from the 3GPP2 organization. The actual wirelesscommunication standard and the multiple access technology employed willdepend on the specific application and the overall design constraintsimposed on the system.

The radio protocol architecture may take on various forms depending onthe particular application. An example for an HSPA system will now bepresented with reference to FIG. 12. FIG. 12 is a conceptual diagramillustrating an example of the radio protocol architecture for the userand control planes.

Turning to FIG. 12, the radio protocol architecture for the UE and NodeB is shown with three layers: Layer 1, Layer 2, and Layer 3. The UEand/or Node B may be receiving entity 110 or transmitting entity 150 inan aspect where receiving entity 110 and transmitting entity 150 arepeer RLC devices. In an aspect where receiving entity 110 andtransmitting entity 150 are protocol layers within a single device,receiving entity 110 and transmitting entity 150 may be any one ofLayers 1, 2, and/or 3 within UE and/or Node B.

Layer 1 is the lowest lower and implements various physical layer signalprocessing functions. Layer 1 will be referred to herein as the physicallayer 1206. Layer 2 (L2 layer) 1208 is above the physical layer 1206 andis responsible for the link between the UE and node B over the physicallayer 1206.

In the user plane, the L2 layer 1208 includes a media access control(MAC) sublayer 1210, a radio link control (RLC) sublayer 1212, and apacket data convergence protocol (PDCP) 1214 sublayer, which areterminated at the node B on the network side. Although not shown, the UEmay have several upper layers above the L2 layer 1208 including anetwork layer (e.g., IP layer) that is terminated at a PDN gateway onthe network side, and an application layer that is terminated at theother end of the connection (e.g., far end UE, server, or the like).

The PDCP sublayer 1214 provides multiplexing between different radiobearers and logical channels. The PDCP sublayer 1214 also providesheader compression for upper layer data packets to reduce radiotransmission overhead, security by ciphering the data packets, andhandover support for UEs between Node Bs. The RLC sublayer 1212 providessegmentation and reassembly of upper layer data packets, retransmissionof lost data packets, and reordering of data packets to compensate forout-of-order reception due to hybrid automatic repeat request (HARQ).The MAC sublayer 1210 provides multiplexing between logical andtransport channels. The MAC sublayer 1210 is also responsible forallocating the various radio resources (e.g., resource blocks) in onecell among the UEs. The MAC sublayer 1210 is also responsible for HARQoperations.

FIG. 13 is a block diagram of a Node B 1310 in communication with a UE1350, where the Node B 1310 and/or UE 1350 may be receiving entity 110and/or transmitting entity 150. In the downlink communication, atransmit processor 1320 may receive data from a data source 1312 andcontrol signals from a controller/processor 1340. The transmit processor1320 provides various signal processing functions for the data andcontrol signals, as well as reference signals (e.g., pilot signals). Forexample, the transmit processor 1320 may provide cyclic redundancy check(CRC) codes for error detection, coding and interleaving to facilitateforward error correction (FEC), mapping to signal constellations basedon various modulation schemes (e.g., binary phase-shift keying (BPSK),quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK),M-quadrature amplitude modulation (M-QAM), and the like), spreading withorthogonal variable spreading factors (OVSF), and multiplying withscrambling codes to produce a series of symbols. Channel estimates froma channel processor 1344 may be used by a controller/processor 1340 todetermine the coding, modulation, spreading, and/or scrambling schemesfor the transmit processor 1320. These channel estimates may be derivedfrom a reference signal transmitted by the UE 1350 or from feedback fromthe UE 1350. The symbols generated by the transmit processor 1320 areprovided to a transmit frame processor 1330 to create a frame structure.The transmit frame processor 1330 creates this frame structure bymultiplexing the symbols with information from the controller/processor1340, resulting in a series of frames. The frames are then provided to atransmitter 1332, which provides various signal conditioning functionsincluding amplifying, filtering, and modulating the frames onto acarrier for downlink transmission over the wireless medium throughantenna 1334. The antenna 1334 may include one or more antennas, forexample, including beam steering bidirectional adaptive antenna arraysor other similar beam technologies.

At the UE 1350, a receiver 1354 receives the downlink transmissionthrough an antenna 1352 and processes the transmission to recover theinformation modulated onto the carrier. The information recovered by thereceiver 1354 is provided to a receive frame processor 1360, whichparses each frame, and provides information from the frames to a channelprocessor 1394 and the data, control, and reference signals to a receiveprocessor 1370. The receive processor 1370 then performs the inverse ofthe processing performed by the transmit processor 1320 in the Node B1310. More specifically, the receive processor 1370 descrambles anddespreads the symbols, and then determines the most likely signalconstellation points transmitted by the Node B 1310 based on themodulation scheme. These soft decisions may be based on channelestimates computed by the channel processor 1394. The soft decisions arethen decoded and deinterleaved to recover the data, control, andreference signals. The CRC codes are then checked to determine whetherthe frames were successfully decoded. The data carried by thesuccessfully decoded frames will then be provided to a data sink 1372,which represents applications running in the UE 1350 and/or various userinterfaces (e.g., display). Control signals carried by successfullydecoded frames will be provided to a controller/processor 1390. Whenframes are unsuccessfully decoded by the receiver processor 1370, thecontroller/processor 1390 also may use an acknowledgement (ACK) and/ornegative acknowledgement (NACK) protocol to support retransmissionrequests for those frames.

In the uplink, data from a data source 1378 and control signals from thecontroller/processor 1390 are provided to a transmit processor 1380. Thedata source 1378 may represent applications running in the UE 1350 andvarious user interfaces (e.g., keyboard). Similar to the functionalitydescribed in connection with the downlink transmission by the Node B1310, the transmit processor 1380 provides various signal processingfunctions including CRC codes, coding and interleaving to facilitateFEC, mapping to signal constellations, spreading with OVSFs, andscrambling to produce a series of symbols. Channel estimates, derived bythe channel processor 1394 from a reference signal transmitted by theNode B 1310 or from feedback contained in the midamble transmitted bythe Node B 1310, may be used to select the appropriate coding,modulation, spreading, and/or scrambling schemes. The symbols producedby the transmit processor 1380 will be provided to a transmit frameprocessor 1382 to create a frame structure. The transmit frame processor1382 creates this frame structure by multiplexing the symbols withinformation from the controller/processor 1390, resulting in a series offrames. The frames are then provided to a transmitter 1356, whichprovides various signal conditioning functions including amplification,filtering, and modulating the frames onto a carrier for uplinktransmission over the wireless medium through the antenna 1352.

The uplink transmission is processed at the Node B 1310 in a mannersimilar to that described in connection with the receiver function atthe UE 1350. A receiver 1335 receives the uplink transmission throughthe antenna 1334 and processes the transmission to recover theinformation modulated onto the carrier. The information recovered by thereceiver 1335 is provided to a receive frame processor 1336, whichparses each frame, and provides information from the frames to thechannel processor 1344 and the data, control, and reference signals to areceive processor 1338. The receive processor 1338 performs the inverseof the processing performed by the transmit processor 1380 in the UE1350. The data and control signals carried by the successfully decodedframes may then be provided to a data sink 1339 and thecontroller/processor, respectively. If some of the frames wereunsuccessfully decoded by the receive processor, thecontroller/processor 1340 also may use an acknowledgement (ACK) and/ornegative acknowledgement (NACK) protocol to support retransmissionrequests for those frames.

The controller/processors 1340 and 1390 may be used to direct theoperation at the Node B 1310 and the UE 1350, respectively. For example,the controller/processors 1340 and 1390 may provide various functionsincluding timing, peripheral interfaces, voltage regulation, powermanagement, and other control functions. The computer readable media ofmemories 1342 and 1392 may store data and software for the Node B 1310and the UE 1350, respectively. A scheduler/processor 1346 at the Node B1310 may be used to allocate resources to the UEs and schedule downlinkand/or uplink transmissions for the UEs.

As used in this application, the terms “component,” “module,” “system”and the like are intended to include a computer-related entity, such asbut not limited to hardware, firmware, a combination of hardware andsoftware, software, or software in execution. For example, a componentmay be, but is not limited to being, a process running on a processor, aprocessor, an object, an executable, a thread of execution, a program,and/or a computer. By way of illustration, both an application runningon a computing device and the computing device can be a component. Oneor more components can reside within a process and/or thread ofexecution and a component may be localized on one computer and/ordistributed between two or more computers. In addition, these componentscan execute from various computer readable media having various datastructures stored thereon. The components may communicate by way oflocal and/or remote processes such as in accordance with a signal havingone or more data packets, such as data from one component interactingwith another component in a local system, distributed system, and/oracross a network such as the Internet with other systems by way of thesignal.

Furthermore, various aspects are described herein in connection with aterminal, which can be a wired terminal or a wireless terminal. Aterminal can also be called a system, device, subscriber unit,subscriber station, mobile station, mobile, mobile device, remotestation, remote terminal, access terminal, user terminal, terminal,communication device, user agent, user device, or user equipment (UE). Awireless terminal may be a cellular telephone, a satellite phone, acordless telephone, a Session Initiation Protocol (SIP) phone, awireless local loop (WLL) station, a personal digital assistant (PDA), ahandheld device having wireless connection capability, a computingdevice, or other processing devices connected to a wireless modem.Moreover, various aspects are described herein in connection with a basestation. A base station may be utilized for communicating with wirelessterminal(s) and also may be referred to as an access point, a Node B, orsome other terminology.

Moreover, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or.” That is, unless specified otherwise, or clearfrom the context, the phrase “X employs A or B” is intended to mean anyof the natural inclusive permutations. That is, the phrase “X employs Aor B” is satisfied by any of the following instances: X employs A; Xemploys B; or X employs both A and B. In addition, the articles “a” and“an” as used in this application and the appended claims shouldgenerally be construed to mean “one or more” unless specified otherwiseor clear from the context to be directed to a singular form.

The techniques described herein may be used for various wirelesscommunication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and othersystems. The terms “system” and “network” are often usedinterchangeably. A CDMA system may implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), cdma2000, or the like UTRAincludes Wideband-CDMA (W-CDMA) and other variants of CDMA. Further,cdma2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA system mayimplement a radio technology such as Global System for MobileCommunications (GSM). An OFDMA system may implement a radio technologysuch as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, or the like UTRAand E-UTRA are part of Universal Mobile Telecommunication System (UMTS).3GPP Long Term Evolution (LTE) is a release of UMTS that uses E-UTRA,which employs OFDMA on the downlink and SC-FDMA on the uplink. UTRA,E-UTRA, UMTS, LTE and GSM are described in documents from anorganization named “3rd Generation Partnership Project” (3GPP).Additionally, cdma2000 and UMB are described in documents from anorganization named “3rd Generation Partnership Project 2” (3GPP2).Further, such wireless communication systems may additionally includepeer-to-peer (e.g., mobile-to-mobile) ad hoc network systems often usingunpaired unlicensed spectrums, 802.xx wireless LAN, BLUETOOTH and anyother short- or long-range, wireless communication techniques.

Various aspects or features will be presented in terms of systems thatmay include a number of devices, components, modules, and the like. Itis to be understood and appreciated that the various systems may includeadditional devices, components, modules, or the like and/or may notinclude all of the devices, components, modules or the like discussed inconnection with the figures. A combination of these approaches also maybe used.

The various illustrative logics, logical blocks, modules, and circuitsdescribed in connection with the embodiments disclosed herein may beimplemented or performed with a general purpose processor, a digitalsignal processor (DSP), an application specific integrated circuit(ASIC), a field programmable gate array (FPGA) or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general-purpose processor may be a microprocessor,but, in the alternative, the processor may be any conventionalprocessor, controller, microcontroller, or state machine. A processoralso may be implemented as a combination of computing devices, e.g., acombination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration. Additionally, at least oneprocessor may comprise one or more modules operable to perform one ormore of the steps and/or actions described above.

Further, the steps and/or actions of a method or algorithm described inconnection with the aspects disclosed herein may be embodied directly inhardware, in a software module executed by a processor, or in acombination of the two. A software module may reside in RAM memory,flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a harddisk, a removable disk, a CD-ROM, or any other form of storage mediumknown in the art. An exemplary storage medium may be coupled to theprocessor, such that the processor can read information from, and writeinformation to, the storage medium. In the alternative, the storagemedium may be integral to the processor. Further, in some aspects, theprocessor and the storage medium may reside in an ASIC. Additionally,the ASIC may reside in a user terminal In the alternative, the processorand the storage medium may reside as discrete components in a userterminal. Additionally, in some aspects, the steps and/or actions of amethod or algorithm may reside as one or any combination or set of codesand/or instructions on a machine readable medium and/or computerreadable medium, which may be incorporated into a computer programproduct.

In one or more aspects, the functions described may be implemented inhardware, software, firmware, or any combination thereof. If implementedin software, the functions may be stored or transmitted as one or moreinstructions or code on a computer-readable medium. Computer-readablemedia includes both computer storage media and communication mediaincluding any medium that facilitates transfer of a computer programfrom one place to another. A storage medium may be any available mediathat can be accessed by a computer. By way of example, and notlimitation, such computer-readable media can comprise RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store desired program code in the form of instructions or datastructures and that can be accessed by a computer. Also, any connectionmay be termed a computer-readable medium. For example, if software istransmitted from a website, server, or other remote source using acoaxial cable, fiber optic cable, twisted pair, digital subscriber line(DSL), or wireless technologies such as infrared, radio, and microwave,then the coaxial cable, fiber optic cable, twisted pair, DSL, orwireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,includes compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk and blu-ray disc where disks usually reproducedata magnetically, while discs usually reproduce data optically withlasers. Combinations of the above should also be included within thescope of computer-readable media.

While the foregoing disclosure discusses illustrative aspects and/orembodiments, it should be noted that various changes and modificationscould be made herein without departing from the scope of the describedaspects and/or embodiments as defined by the appended claims.Furthermore, although elements of the described aspects and/orembodiments may be described or claimed in the singular, the plural iscontemplated unless limitation to the singular is explicitly stated.Additionally, all or a portion of any aspect and/or embodiment may beutilized with all or a portion of any other aspect and/or embodiment,unless stated otherwise.

What is claimed is:
 1. A method for wireless communication, comprising: transmitting at least one protocol data unit (PDU) from a transmitting entity to a receiving entity, wherein the at least one PDU is part of a service data unit (SDU); determining to perform a communication re-establishment; and retransmitting the SDU, beginning with a first PDU transmitted as part of the SDU, in response to determining to perform the communication re-establishment.
 2. The method of claim 1, wherein the transmitting entity is a radio link control (RLC) transmitting device and the receiving entity is an RLC receiving device in communication with one another across a network.
 3. The method of claim 2, wherein the determining to perform the communication re-establishment comprises: initiating an SDU discard procedure; and determining that the SDU discard procedure has been successfully completed, and wherein the retransmitting the SDU to the RLC receiving device comprises retransmitting beginning at a first byte of the SDU.
 4. The method of claim 3, wherein the initiating is based on receiving a radio link control (RLC) RESET command from the RLC receiving device, and further comprising transmitting an RLC RESET command acknowledgement message to the RLC receiving device based on determining that the SDU discard procedure has been successfully completed.
 5. The method of claim 3, wherein the initiating is based on sending a radio link control (RLC) RESET command to the RLC receiving device, and wherein the determining that the SDU discard procedure has been successfully completed comprises receiving an RLC RESET command acknowledgment message from the RLC receiving device, wherein the acknowledgment message indicates that the SDU discard procedure has been successfully completed.
 6. The method of claim 3, wherein determining that the SDU discard procedure has been successfully completed comprises: transmitting a move receive window (MRW) command to the RLC receiving device; and receiving an MRW command acknowledgement message from the receiving device indicating that the RLC receiving device has discarded the SDU and has moved a receive window in preparation for receiving a retransmitted SDU.
 7. The method of claim 3, wherein determining that the SDU discard procedure has been successfully completed comprises: receiving a move receive window (MRW) command from the RLC receiving device; and transmitting an MRW command acknowledgment message to the receiving device indicating that the RLC transmitting device has discarded the SDU and has moved a receive window in preparation for receiving a retransmitted SDU.
 8. The method of claim 3, further comprising performing the SDU discard procedure, including: determining that at least one or more PDUs associated with the SDU have not been acknowledged by the RLC receiving device; and moving the SDU associated with the one or more unacknowledged PDUs to a transmission queue in an original order for retransmission of the SDU to the RLC receiving device.
 9. The method of claim 1, wherein the transmitting entity is a radio link control (RLC) transmitting protocol layer and the receiving entity is a radio link control (RLC) receiving protocol layer both within a protocol stack of a device.
 10. The method of claim 9, wherein the transmitting comprises transmitting from the RLC transmitting protocol layer to the RLC receiving protocol layer, and wherein the determining to perform the communication re-establishment comprises: receiving a message indicating the communication re-establishment; determining that the communication re-establishment has been successfully completed; and retransmitting the SDU comprises retransmitting, beginning at a first byte of the SDU, to the RLC receiving protocol layer.
 11. The method of claim 10, wherein the message comprises a layer 3 (L3) message.
 12. The method of claim 10, wherein the initiating is based on receiving a radio link control (RLC) RE-ESTABLISHMENT command from the RLC receiving protocol layer, and further comprising transmitting an acknowledgement message to the RLC receiving protocol layer based on determining that the re-establishment has been successfully completed.
 13. A computer program product for wireless communication, comprising: a computer-readable medium comprising: code for causing a computer to: transmit at least one protocol data unit (PDU) from a transmitting entity to a receiving entity, wherein the at least one PDU is part of a service data unit (SDU); determine to perform a communication re-establishment; and retransmit the SDU, beginning with a first PDU transmitted as part of the SDU, in response to determining to perform the communication re-establishment.
 14. An apparatus for wireless communication, comprising: means for transmitting at least one protocol data unit (PDU) from a transmitting entity to a receiving entity, wherein the at least one PDU is part of a service data unit (SDU); means for determining to perform a communication re-establishment; and means for retransmitting the SDU, beginning with a first PDU transmitted as part of the SDU, in response to determining to perform the communication re-establishment.
 15. An apparatus for wireless communication, comprising: at least one memory; and a communication manager in communication with the memory and configured to: transmit at least one protocol data unit (PDU) from a transmitting entity to a receiving entity, wherein the at least one PDU is part of a service data unit (SDU); determine to perform a communication re-establishment; and retransmit the SDU, beginning with a first PDU transmitted as part of the SDU, in response to determining to perform the communication re-establishment.
 16. The apparatus of claim 15, wherein the transmitting entity is a radio link control (RLC) transmitting device and the receiving entity is an RLC receiving device in communication with one another across a network.
 17. The apparatus of claim 16, wherein the communication manager being configured to determine to perform the communication re-establishment comprises the communication manager configured to: initiate an SDU discard procedure; and determine that the SDU discard procedure has been successfully completed, and wherein the communication manager being configured to retransmit the SDU to the RLC receiving device comprises the communication manager being configured to retransmit beginning at a first byte of the SDU.
 18. The apparatus of claim 17, wherein the communication manager being configured to initiate the SDU discard procedure is based on the communication manager configured to receive a radio link control (RLC) RESET command from the RLC receiving device, and further comprising the communication manager configured to transmit an RLC RESET command acknowledgement message to the RLC receiving device based on the communication manager configured to determine that the SDU discard procedure has been successfully completed.
 19. The apparatus of claim 17, wherein the communication manager being configured to initiate is based on the communication manager configured to send a radio link control (RLC) RESET command to the RLC receiving device, and wherein the communication manager being configured to determine that the SDU discard procedure has been successfully completed comprises the communication manager configured to receive an RLC RESET command acknowledgment message from the RLC receiving device, wherein the acknowledgment message indicates that the SDU discard procedure has been successfully completed.
 20. The apparatus of claim 17, wherein the communication manager being configured to determine that the SDU discard procedure has been successfully completed comprises the communication manager configured to: transmit a move receive window (MRW) command to the RLC receiving device; and receive an MRW command acknowledgement message from the receiving device indicating that the RLC receiving device has discarded the SDU and has moved a receive window in preparation for receiving a retransmitted SDU.
 21. The apparatus of claim 17, wherein the communication manager being configured to determine that the SDU discard procedure has been successfully completed comprises the communication manager configured to: receive a move receive window (MRW) command from the RLC receiving device; and transmit an MRW command acknowledgment message to the receiving device indicating that the RLC transmitting device has discarded the SDU and has moved a receive window in preparation for receiving a retransmitted SDU.
 22. The apparatus of claim 17, further comprising the communication manager configured to perform the SDU discard procedure, including the communication manager configured to: determine that at least one or more PDUs associated with the SDU have not been acknowledged by the RLC receiving device; and move the SDU associated with the one or more unacknowledged PDUs to a transmission queue in an original order for retransmission of the SDU to the RLC receiving device.
 23. The apparatus of claim 15, wherein the transmitting entity is a radio link control (RLC) transmitting protocol layer and the receiving entity is a radio link control (RLC) receiving protocol layer both within a protocol stack of a device.
 24. The apparatus of claim 23, wherein the communication manager being configured to transmit comprises the communication manager configured to transmit from the RLC transmitting protocol layer to the RLC receiving protocol layer, and wherein the communication manager being configured to determine to perform the communication re-establishment comprises the communication manager configured to: receive a message indicating the communication re-establishment; determine that the communication re-establishment has been successfully completed; and retransmit the SDU comprises retransmitting, beginning at a first byte of the SDU, to the RLC receiving protocol layer.
 25. The apparatus of claim 24, wherein the message comprises a layer 3 (L3) message.
 26. The apparatus of claim 24, wherein the communication manager being configured to initiate is based on the communication manager configured to receive a radio link control (RLC) RE-ESTABLISHMENT command from the RLC receiving protocol layer, and further comprising the communication manager configured to transmit an acknowledgement message to the RLC receiving protocol layer based on the communication manager being configured to determine that the re-establishment has been successfully completed. 